The invention relates to a process for the production of a composite sheet comprising a cellular core with at least one outer layer by bonding the outer layer to the cellular core with the aid of adhesive, adhesive where applied to the cellular core, and the outer layer is subsequently applied and bonded to the cellular core under pressure and at elevated temperature. The invention also relates to the composite sheets produced by the process, and to their use.
On bonding of cellular cores and outer layers, an adhesive can in principle only be effective at the points of contact between the cellular core and the outer layers. A significant disadvantage of adhesive processes is that the adhesive, applied over the entire surface, will not be located in increased amounts at the points of contact between the cellular core and the outer layer.
GB 2,096,535 A describes a process for bonding a honeycomb core to at least one perforated element in which an adhesive film is applied to the perforated element or to the honeycomb core.
The adhesive bonds disclosed hitherto between honeycomb cores and outer layers have not been able to satisfy all the demands made, for example with respect to delamination or separation strength of the layers. The object of the present invention is to overcome said disadvantages.